Convalescent plasma and predictors of mortality among hospitalized patients with COVID-19: a systematic review and meta-analysis

COVID-19 Vaccination in Patients with Hematological Malignances

Patients with hematologic malignancies (HM) represent a population particularly vulnerable to infections due to their cancer-related immune deficiency and the immunosuppressive treatment they are administered. Accordingly, a high hospitalization and mortality rate has been consistently reported in such a frail population during the first COVID-19 pandemic waves. After a brief description of the clinical impact of SARS-CoV-2 infection in patients with blood cancers, this narrative review is focused on the protective effect of COVID-19 vaccines in patients with HM. All in all, the results from the literature analysis indicate that booster shots in fully vaccinated HM patients are significantly able to increase seroconversion rates, which represent the best surrogate of vaccine efficacy. Despite these encouraging data, concerns still remain regarding the lower immune responses to COVID-19 vaccines, even to booster doses, in severely immunosuppressed HM patients, such as those receiving anti-CD20 monoclonal antibody therapies and hematopoietic stem cell transplants.

Development of antiviral drugs for COVID-19 in 2025: unmet needs and future challenges

INTRODUCTION

The success in the coronavirus infectious disease 2019 (COVID-19) pandemic containment largely originated from vaccine- and infection-elicited immunity, with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection only marginally mitigated by the availability of antiviral drugs. The current lack of effective antiviral prophylactic and therapeutic agents in immunocompromised patients highlights the need for a radical change in the design of both drug manufacturing and clinical trials.

AREAS COVERED

In this review, the authors summarize their suggestions for manufacturers, by reviewing classes of small molecule antivirals and passive immunotherapies and highlighting their limitations and unexploited potential.

EXPERT OPINION

Molecular and serological testing of patients can improve appropriateness. Efficacy of antivirals can be improved by combining different therapeutic classes while preserving economical sustainability. Respiratory delivery should be better investigated in clinical trials.

Individual patient and donor seroprofiles in convalescent plasma treatment of COVID-19 in REMAP-CAP clinical trial

OBJECTIVES

Convalescent plasma (CP) treatment of COVID-19 has shown significant therapeutic effect only when administered early. We investigated the importance of patient and CP seroprofiles on treatment outcome in REMAP-CAP CP trial.

METHODS

We evaluated neutralising antibodies (nAb), anti-spike (S) IgM, IgG, IgG avidity, IgG fucosylation and respiratory viral loads in a sub-set of patients (n=80) and controls (n=51) before and after transfusion, comparing them to those in the CP units (n=157) they received.

RESULTS

Most patients were SARS-CoV-2 seropositive pre-transfusion (72% nAb; 89% S-IgG seropositivity). The majority (80%) had higher pre-transfusion S-IgG levels (median 1.7×106 arbitrary units (AU); 56%) or S-IgG production rates (median 1.1×106 AU/day; 64%) than they received from CP (median 2.2×105 AU). Only 22% of the patients demonstrated significant (median 24-fold) increase in their S-IgG levels acquired from transfusion. Better outcomes, measured by organ support-free days, were associated with increase in S-IgM levels (p=0.007), decreased S-IgG fucosylation (p<0.001), lower patient age (p<0.001) but not with receiving CP (p=0.337).

CONCLUSIONS

Based on our data, increased S-antibody levels linked to transfused CP were only observed in pre-seroconversion or immunodeficient patients lacking their own SARS-CoV-2 antibodies, representing the groups where CP treatment has previously shown most benefit.

Using Passive Antibody Therapies in the Next Pandemic

The twenty-first century has witnessed seven human viral pandemics. Approximately once every three to four years over the past quarter-century, the world has experienced a new viral epidemic that expanded well beyond its original national borders to become a pandemic. The probability that another pandemic caused by a previously unknown agent will occur in the near future is thus very high and public health agencies must prioritize mechanisms for detecting their first signals. At the onset of these recent pandemics, no specific therapeutic agent was available for any of the newly emergent pathogens. However, convalescent plasma therapy can be available as soon as there are survivors and is likely to be effective if used early and in sufficient strength. But for the three forms of passive antibody-convalescent plasma, monoclonal antibodies, and hyperimmune globulins-to be available and effective in a pandemic situation, careful strategic planning will be necessary. In the pre-pandemic period, we must reinforce the capacities of blood banks and plasma fractionating companies in the production and storage of their products; ensure that outpatient settings can provide intravenous products; educate providers in the proper use of plasma; and create a research infrastructure to examine the effectiveness of passive antibody products. Once a pandemic is underway, regulatory bodies should simplify the approval of research and emergency use protocols and develop treatment registries. Incentives for the rapid production of monoclonal antibodies and hyperimmune globulins will likely be required. A national resource to link providers with passive antibody products and national databases to monitor pandemic progress and pandemic treatment will permit the most effective allocation of pandemic-fighting resources. We cannot afford to wait until the next pandemic is upon us to respond. The time to strengthen clinical, research, and manufacturing infrastructure to permit us to be ready to confront the next new virulent pathogen is now.

Estimates of actual and potential lives saved in the United States from the use of COVID-19 convalescent plasma

In the Spring of 2020, the United States of America (USA) deployed COVID-19 convalescent plasma (CCP) to treat hospitalized patients. Over 500,000 patients were treated with CCP during the first year of the pandemic. In this study, we estimated the number of actual inpatient lives saved by CCP treatment in the United States of America based on CCP weekly use, weekly national mortality data, and CCP mortality reduction data from meta-analyses of randomized controlled trials and real-world data. We also estimate the potential number of lives saved if CCP had been deployed for 100% of hospitalized patients or used in 15 to 75% of outpatients. Depending on the assumptions modeled in stratified analyses, we estimated that CCP saved between 16,476 and 66,296 lives. The CCP ideal use might have saved as many as 234,869 lives and prevented 1,136,133 hospitalizations. CCP deployment was a successful strategy for ameliorating the impact of the COVID-19 pandemic in the USA. This experience has important implications for convalescent plasma use in future infectious disease emergencies.

Avoided and Avoidable Deaths with the Use of COVID-19 Convalescent Plasma in Italy during the First Two Years of Pandemic

Italy was the first western country to be hit by the COVID-19 pandemic and has suffered nearly 200,000 deaths so far during the four years of the pandemic. In March 2020, Italy first deployed COVID-19 convalescent plasma (CCP) to treat hospitalized patients. Despite this initial effort, the proportion of COVID-19 patients treated with CCP during the first two years of the pandemic (2020-2021) was very low (approximately 2% of individuals hospitalized for COVID-19). In this study, we estimated the number of actual inpatient lives saved by CCP treatment in Italy using national mortality data, and CCP mortality reduction data from meta-analyses of randomized controlled trials and real-world data. We also estimated the potential number of lives saved if CCP had been deployed to 100% of hospitalized patients or used in 15% to 75% of outpatients. According to these models, CCP usage in 2020-2021 saved between 385-1304 lives, but this number would have increased to 17,751-60,079 if 100% of inpatients had been transfused with CCP. Similarly, broader (15-75%) usage in outpatients could have prevented 21,187-190,689 hospitalizations (desaturating hospitals) and 6144-81,926 deaths. These data have important implications for convalescent plasma use in future infectious disease emergencies.